The invention relates to a motor vehicle equipped with a device that detects when the driver of a motor vehicle is about to shift gear; and it further relates to a method of detecting when a gear shift is about to occur.
Motor vehicles with a device for detecting a driver""s intention to shift gear are known from DE 197 34 038 A1. The device according to the aforementioned publication is based on a sensor that is arranged at the actuating linkage of the transmission. When the sensor detects a move to change the position of the actuating linkage, the activity is interpreted as a signal that the driver intends to shift gear, whereupon the signal is forwarded to a clutch control device. After the driver""s intent to shift gear has been recognized, the clutch control device issues a control command for the clutch to be taken out of engagement.
This known device is especially appropriate for motor vehicles without a clutch pedal, where the driver initiates a gear change in the transmission only through a shift lever.
A motor vehicle with a device for detecting a driver""s intention to shift gear is further known from DE 195 04 847.1, which describes a device that detects the magnitude of a change in the shift lever position and generates a shift lever signal of proportionate magnitude as the change in the shift lever position. The shift lever signal is processed through a digital/analog filter with a time lag, so that the filtered signal comes out as a linearized signal with a time delay in relation to the movement of the shift lever. A reference level for the filtered signal is generated by combining a constant value with an offset signal that depends on the magnitude of a torque in the power train of the vehicle. As soon as there is a cross-over in a real-time comparison between the shift signal and the reference signal, a shift-intent counter is set to start counting up from zero. The shift-intent counter runs up to a defined reference count at a speed that depends on the clock frequency of the control unit. As soon as the shift-intent counter has reached the reference value, it sends a shift-intent signal to an actuator system. While the shift-intent counter is incrementing from zero towards the reference value, the count can be stopped and reset to zero, if a control signal based on the driving torque, the torque load on the power train, and the further movement of the shift lever indicates that the driver no longer intends to shift gear.
With the device of the foregoing description, an intention to shift gear can be detected at a relatively early stage.
Nevertheless, in certain situations, the device of the foregoing description could benefit from improvements with respect to its accuracy and responsiveness. In particular, it would be desirable to give more weight to operational, vehicle-specific, and situational parameters in the detection of an intent to shift gear.
The object of the present invention is to provide a vehicle with a capability to detect when a driver intends to shift gear through a concept that is cost-effective, uncomplicated to realize, detects an incipient gear shift promptly and reliably, takes vehicle-specific and operational parameters into account, and responds to each shift situation in an optimally adapted manner.
The present invention meets the foregoing objective in a motor vehicle with at least one drive source and at least one output device in its power train, and at least one transmission device arranged in the power train between the drive source and the output device. The transmission device converts a transmission input quantity into a transmission output quantity and is operable to shift gear, i.e., to change the transmission from one to another of at least two different gear levels with different ratios between an input quantity and an output quantity of the transmission. At least one actuating device is used to actuate the shifting of the transmission device. The vehicle is equipped with at least one detecting device (herein referred to as an intent-to-shift detecting device) that is responsive to conditions or activities indicating that the driver of the vehicle intends to shift gear. The vehicle further has at least one detector system to monitor one or more vehicle components for the presence of performance-affecting conditions that have an influence on the shifting of the transmission device.
Such performance-affecting conditions can be caused, e.g., by production-related or wear-related variances of a component, and are characterized by associated operating parameters of the vehicle. Typically, the intent-to-shift detecting device generates a signal when an intent to shift gear has been detected. In a preferred embodiment of the present invention, the motor vehicle is equipped with one or more adaptation devices to adapt the intent-to-shift signal to the performance-affecting condition.
The scope of the present invention also encompasses a method of detecting a driver""s intent to shift gear in a motor vehicle with one or more transmission devices and one or more shifting devices. With the inventive method, the intent to shift is detected in accordance with a set of detection characteristics, where a degree of mechanical play in the transmission device and/or the shifting device is taken into account to an at least partial extent.
Thus, the invention provides that a motor vehicle be equipped with one or more transmission devices, one or more actuating devices for the transmission device, at least one intent-to-shift detection device, as well as at least one detector system to detect conditions which may be related to vehicle components and/or to a signal indicating an intent to shift gear and/or to a signal from the shift lever, and/or to the function of the shift lever.
The motor vehicle has a drive source such as any kind of motor, e.g., an electric motor, or a combustion engine. The drive source generates a mechanical drive quantity which may be, for example, of an electrical or mechanical nature, such as a torque.
An output device of the motor vehicle serves to produce one or more output quantities, such as for example a mechanical output quantity, specifically a torque acting on the drive wheels of the motor vehicle.
The transmission device serves to convert a transmission input quantity into a transmission output quantity. For example, a torque of a transmission input shaft may be converted into a torque of a transmission output shaft. Preferably, the transmission has a neutral position, in which a torque at the input shaft does not result in a torque on the output shaft, and vice versa. With particular preference, the transmission device has different shift levels, commonly referred to as different gears, gear levels, etc. The shift levels or gear levels are distinguished in that each produces a different transmission ratio, i.e., a different ratio between the respective rpm rates of the transmission input shaft and the transmission output shaft.
A particularly preferred kind of transmission is a gear-shifting transmission, where discrete gear levels are clearly defined and are shifted in stepwise sequence.
According to a further preferred embodiment of the invention, the transmission device is configured at least in part as a step-less transmission, in which the transmission ratio has a continuous rather range of variation rather than discrete steps.
It is also preferred if the transmission is at least in part an automatic transmission or an automated gear-shifting transmission.
A vehicle according to a preferred embodiment of the invention is equipped with a torque-transmitting device such as, e.g., a clutch.
Also among preferred concepts of the invention are configurations of the torque-transmitting device with or without a power-branching arrangement.
In place of, or in addition to, a clutch, the torque transmitting device may also include a torque-converter device.
In accordance with a preferred embodiment of the invention, the torque-transmitting device is arranged in the torque flow path between the drive source and the transmission device.
In an alternative preferred embodiment, the transmission device is arranged in the torque flow path between the drive source and the torque-transmitting device.
According to the invention, the intent-to-shift detecting device provides the capability of detecting an incipient shift activity of the shift lever or the transmission, i.e., a condition where a gear shift is about to occur and/or has just been initiated.
The inventive concept also provides for the detection of extraneous influences and interference factors that affect the gear-shifting functions of the actuating device and/or the shifting device and/or the transmission itself.
These extraneous influences or interference factors can be rooted in the design of vehicle components, in the shift signal, as well as in factors that have an influence on the shift signal. For example, such interference factors can be related to the design of the shift lever, the mounting arrangement of the shift lever, or a signal that either acts on or is generated by the shift lever. Material-related factors, too, such as for example the elasticity of the shift lever, can be picked up and taken into account by the detecting arrangement. By entering all of the acquired signal data into the intent-to-shift detection arrangement, the presence of an intent to shift gears can be established accurately and reliably.
The invention provides the benefit that it improves the accuracy, precision, reliability, as well as reproducibility in detecting the presence of an intent to shift gears. The intent-to-shift detection device is configured preferably as an intelligent controller device. In addition to the aforementioned benefits, it has a cost-effective design and does not require a large manufacturing investment. Furthermore, the device according to the invention reduces the incidence of erroneous data. Although the latter could be corrected after they have occurred, the correction would increase the data processing requirements. As a further benefit, the invention provides the possibility of a learning process whereby parameter data that are uniquely specific to an individual vehicle can be acquired with high accuracy and subsequently used to optimize the detection process specifically for an individual vehicle, as compared to a less advanced concept of adapting the parameter data only to the vehicle type.
The invention further proposes the concept of an adapting device. The latter allows at least one signal to be adapted to production-related and/or wear-related vehicle parameters. For example, the adapting device can be designed so that a signal sent into or out of the intent-to-shift detection device can be adapted to an appropriate parameter. In accordance with a preferred embodiment of the invention, a signal generated by the intent-to-shift detecting device, such as a reference signal, or an offset signal or constant value entering into the reference signal, can be adapted to a degree of play that is present in the shifting device and/or the transmission device and/or the shift-actuator shaft. For example, the offset signal or the constant value can be adapted to the degree of play found in the force-free positions of a shift lever.
In particular, the invention includes the concept of adapting the reference signal and/or the offset signal and/or the constant value to wear -related changes of vehicle parameters, such as a wear-related play of the shift leverxe2x80x94preferably in the force-free positions of the shift lever or the shift-actuator shaft. Thus, the invention provides for example that the offset signal and/or the constant value be determined also in function of the shift lever play. With particular preference, the correction or adjustment or adaptation of at least one of the aforementioned signals is made while the vehicle is in operation.
According to a further preferred embodiment of the invention, the actuating device includes a shifting device. The shifting device allows a shift signal or a shift lever signal to be directly or indirectly introduced and/or generated. For example, the shift signal can be transmitted through an intermediate device to the transmission, causing the latter to shift into a different position.
With preference, the shifting device is a shift lever or includes a shift lever. According to a particularly preferred embodiment, the lever or shifting device is manually operable. The term xe2x80x9cmanually operablexe2x80x9d is used here with a general meaning. Thus, the attribute xe2x80x9cmanually operablexe2x80x9d also includes the case, for example, where the driver of a vehicle manually operates a shift lever from which an either direct or modified command signal is sent to the shifting device and/or to a clutch device that is part of the vehicle.
The term xe2x80x9cmanually operablexe2x80x9d also includes the case where the driver of a vehicle actuates an appropriate lever or shifting device through a foot pedal.
The invention also covers an arrangement where the actuation of a shift lever to initiate a shifting process in the transmission simultaneously initiates a corresponding actuator movement in the torque-transmitting device, such as a clutch, in which case it is of particular advantage if the detection of the driver""s intention to shift gear is precise and reliable.
Nevertheless, the invention also includes an arrangement where a torque-transmitting device such as a clutch is operable by a separate actuating element such as a foot- or hand-operated lever.
In accordance with a preferred embodiment of the invention, the actuating device for the transmission includes an intermediate shifting device by which at least one shift signal can be transmitted from the shifting device to the transmission device. The shift signal is transmitted preferably at certain times, i.e., in the presence of certain criteria.
The intermediate shifting device is for example a mechanical device, but the range of preferred embodiments also includes electrical and/or electromagnetic intermediate shifting devices.
With preference, the transmission or the intermediate shifting device includes at least one shift-actuator shaft. A component such as the shift-actuator shaft is equipped preferably with at least part of a detent-stop arrangement to define one or more positions so that they can be replicated when operating the component.
Particularly in a mechanical configuration, the preferred arrangement has at least two elements that are movable in relation to each other inside the transmission device and/or the actuating device and/or the shifting device and/or the intermediate device.
For example, the shifting device includes a shift lever which is movable at least part of the time within defined tracks. For example, the shifting device may be configured according to an H-shaped shift pattern, where a shift lever is moveable along the different segments of a path resembling the letter H.
According to a further preferred embodiment of the invention, the H-pattern of the shifting device has at least one shifting segment and at least one selecting segment. Preferably, a shifting segment is assigned to each shift level of the transmission. With particular preference, a shift lever can be moved to a defined position or range of positions in the shifting segment corresponding essentially to a specific position of the transmission device where the latter is at a specific predetermined shift level with a specific transmission ratio.
A particularly preferred arrangement of the H-pattern has one shifting segment for each shift level.
In accordance with a further preferred arrangement, a selecting segment is arranged at least partially between the shifting segments.
Thus, in a preferred shifting arrangement, the shift movement from first to second gear first leads through at least part of a shifting segment, then traverses or at least partially follows the selecting segment, then enters another shifting segment to reach the position assigned to second gear.
In a preferred shift layout, the shifting and selecting segments alternate in a meandering pattern.
Also preferred are shift patterns where at least two shifting segments open into a selecting segment. For example, all of the shifting segments may terminate into exactly one selecting segment.
According to a further preferred embodiment of the invention, the transmission device is equipped with a reverse gear. Preferably, the transmission device has a specific segment of the shift pattern assigned to reverse gear. With particular preference, the shifting segments of the shift track arrangement are oriented along a first direction while the selecting segment is arranged along at least one second direction that is different from the first direction. For example, alle shifting segments may be arranged parallel to each other in the same direction, while the selecting segment runs in a different direction, e.g., perpendicular to the direction of the shifting segments.
According to a particularly preferred embodiment of the invention, there is a functional relationship between the movement of an element that belongs to the shifting device and/or an element that belongs to the transmission device and/or an element that belongs to the transmission device and/or an element that belongs to the intermediate device. Preferably, the functional relationship holds true at least within certain tolerance intervals. An example is the relationship between the movement of the shift lever and the corresponding movement of the shift-actuator shaft.
According to a further preferred embodiment of the invention, the detector system for detecting component-related influence factors in the shifting process includes at least one play-detecting device to detect a play in a mechanism.
The play-detecting device is used, e.g., to detect the play of a shift lever at least in specific shift lever positions or ranges of positions. For example, the play detecting device may serve to register a degree of play in at least one force-free position of the shift lever and/or the shift-actuator shaft and/or a component coupled to the shift lever. In a preferred arrangement, at least one component whose movement has a functional relationship to the shift lever movement, at least within certain tolerance intervals, is in an essentially force-free position for the detection of the play.
According to a particularly preferred embodiment of the invention, at least one component that is in a force-free position for the detection of play is held in that position by a detent device. It is particularly preferred to detect the deviation of the component from a zero reference position, which may be identical with the detent position. With particular preference, deviations in the shift lever position are registered only if they exceed a certain threshold of, e.g., three scale increments.
It is preferred if the play of the shift lever within a set shift position can be detected. In the process of this detection, an element of the transmission device and/or the intermediate device and/or the shifting device, such as a shift-actuator shaft, is fixed in an essentially set or settable intended position. Preferably, the intended position can be set in a reproducible manner through a detent device. Particularly preferred is an arrangement where the play in the transmission device and/or the intermediate device and/or the shifting device is in essence only the result of a play in the shift lever.
It is particularly preferred if the detector system can detect the play that is related to the shift signal and/or the shift lever signal. The play could be related, e.g., to components engaged with the shift lever and/or to the interaction of components that are movable in relation to each other.
According to a particularly preferred embodiment of the invention, the play-detecting device is designed to detect the play between a first reference location of a first element and at least one second reference location of a second element. For example, the device has the ability to detect the range of positions that a second element can assume that is coupled to a first element, if the first element is essentially in a fixed position. In addition or as an alternative, the device can be configured to detect the extremes of the range of positions that two elements can take on in relation to each other. This implies, e.g., that when a first element is intended to take on a certain nominal position, the element can take an actual position that is different from the intended nominal position. In addition, the play-detecting device can detect the one or more positions or ranges of positions that the second element can assume. Thus, it is possible to detect the actual positions or ranges of positions of the first element in relation to a nominal position of the first element, and also the actual positions of the second element in relation to the nominal position of the first element. It is further possible to detect the actual positions of the second element in relation to the actual positions of the first element. Thus, it is possible, e.g., to detect the play of the first element in relation to its nominal position.
In addition, it is also possible, e.g., to detect the play of the second element in relation to the nominal position of the first element. Further, the play of the second element relative to the first element can be detected, e.g., based on ranges of movement between the first and second element.
Ranges of movement between elements can have a play for a number of different reasons. For example, the mobility of elements in relation to each other can be provided by couplings or links that have a certain amount of play. Also, dimensional variations similar to a play can be cased by material properties of the elements and the couplings or links between them, such as temperature-related changes in length, or load-dependent changes in length.
With preference, one of the aforementioned two elements or reference locations is part of the transmission device, while the second of the two elements if part of the shifting device. Thus, it is possible to determine the play, for example, between a nominal position of a shift-actuator shaft and the position of the shift lever, and/or the play between the actual position of a shift-actuator shaft and the shift lever, and/or the play between the engagement position of the transmission and the position of the shift lever. According to a particularly preferred embodiment of the invention, the play-detecting device is equipped with a strain-sensing device. Preferably, the strain-sensing device serves to determine the strain of individual components and/or the sum of the strains of a plurality of components and, more specifically, the influence of the strains on the shifting process. For example, a strain-sensing device according to the invention serves to determine the strain of at least one element of the shifting device and/or the transmission device and/or the intermediate shifting device and/or the transmission-actuator device and/or the sum of the strains detected in the aforementioned devices.
Also with special preference, the detector system includes a deformation-detecting device. A deformation-detecting device according to the invention serves to detect deformations of the motor vehicle, particularly of the transmission device and/or the intermediate shifting device and/or the shifting device. The data provided by the deformation-detecting device can be evaluated in particular for the purpose of detecting the presence of a damaged condition in a component. The deformation-detecting device is distinguished from the strain-detecting device in that the deformations are not limited to strain-related deformations. The deformation-detecting device as well as the strain-detecting device can be designed for one-, two-, or three-dimensional detection.
With preference, the strain-detecting device as well as the deformation-detecting device or the play-detecting device, or the detector system is coupled to a diagnostic device. With special preference, a diagnostic device according to the invention is equipped with an automatic learning capability. It is also preferred if the diagnostic device can be accessed from the outside. For example, as a preferred concept according to the invention, if during a repair process certain signal values are detected by one of the aforementioned detecting devices, data are collected about the defective conditions diagnosed in the vehicle, based on certain values determined by the detection device. The data are then, e.g. correlated to the values, so that if the same values are found again in the subsequent operation of the vehicle, a probable recurrence of the same defect can be signalled to the driver of the vehicle.
According to a further preferred embodiment of the invention, the detector system qualitatively captures at least one type of information related to a condition which is caused by a component and/or by a shift signal and/or by a shift lever signal and which has an influence on the shift process or on a signal such as a shift signal and/or a reference signal and/or an offset signal and/;or a constant value.
It is particularly preferred if the influence of the aforementioned condition is also determined quantitatively.
According to another preferred embodiment of the invention, the vehicle is equipped with a gear-level detecting device to detect which of two or more shift levels or transmission ratios is engaged. Preferably, the gear-level detecting device has the ability to detect whether the engaged shift level is a permissible shift level for the vehicle to take off from a stand-still condition, e.g., first gear or reverse. Preferably, the shift level detecting device uses a correlation table or the like, which identifies the shift levels that are permissible to take off from a stand-still condition. According to a further preferred embodiment of the invention, the gear-level detecting device has at least one sensor or is at least part of the time connected to a sensor. The sensor may be arranged, for example, at the shift-actuator shaft. Also with preference, a potentiometer arrangement is used to determine which gear is engaged.
A preferred embodiment of a motor vehicle according to the invention has a position-detecting device to detect the current position of the shift lever. With particular preference, the position-detecting device has, either in addition or as an alternative, the capability of detecting the current speed and/or acceleration of a movement of the shift lever. Also with particular preference, the device is capable of detecting the position and/or direction of movement and/or the acceleration and/or the speed of the shift lever in different spatial dimensions. The invention includes, e.g., the concept that the position-detecting device determines the position and/or the direction of movement and/or the speed and/or the acceleration as a vectorial quantity, e.g., as a three-dimensional vector. A preferred embodiment of the motor vehicle according to the invention is equipped with a shifting device with at least one potentiometer. The potentiometer is configured, e.g., as a linear potentiometer. A linear potentiometer is used preferably for detecting the current position of the shift lever. Also, as a particularly preferred arrangement, the shift lever is connected to the potentiometer. It is further preferred, if the detection of the displacement and/or position by the position-detecting device is supplemented by a measurement of elapsed time and the position data are correlated with the corresponding time values. The time values and/or elapsed time intervals can be determined, e.g., dependent on the clock frequency of an on-board computer device. The position values and time values are used preferably to determine the speed and acceleration of the shift lever.
As a particularly preferred concept, the shifting device has two potentiometers arranged at a certain angle to each other, e.g., 90xc2x0. With particular preference, at least one potentiometer is oriented in the direction of a shifting segment, while a second potentiometer is oriented in the direction of a selecting segment. For example, individual potentiometers may be assigned to each of the shifting and selecting segments to determine the position of the shift lever within that segment. It is also a preferred arrangement to have one potentiometer arranged to work for all of the selecting segments and a second potentiometer arranged to work for all of the shifting segments.
The resistance/displacement characteristic of the potentiometers may be identical for all of the potentiometers. However, the scope of preferred arrangements also includes resistance/displacement characteristics that are at least in part different from each other. With particular preference, all of the potentiometers have different resistance/displacement characteristics.
A particularly preferred embodiment of a motor vehicle according to the invention is equipped with a data storage device and/or a data processing device and/or a data evaluating device, e.g., a computer device, to collect, store, process and evaluate the data detected, used or processed by the detector system and/or the different detection devices.
For example, each of the detection devices may be assigned directly to the detector system. However, the detection devices may also be part of another appropriate device that is provided as a standard component of motor vehicles, e.g., a central computer unit. It is also preferred to integrate the aforenamed detecting devices and functions in an electronic clutch management system, or in a clutch control unit.
According to a further preferred embodiment of the invention, the central computer unit or other control unit uses the concept of an operating phase as a time interval. The operating phase begins, e.g., when the engine is started and ends when the engine is turned off.
With particular preference, an operating phase is treated as a unitary time period during which the values determined by the detection devices are processed separately from other operating phases.
It is further preferred to isolate the data values associated with a given operating phase, e.g., by identifying the data values with an index that correlates data values with operating phases. This makes it possible, for example, to combine the data values determined by the detector system with other parameter values that were determined during the same operating phase for a long-term evaluation which, in turn, can be used to uncover long-term trends.
Thus, the invention provides a possibility to determine and evaluate developments occurring within one operating phase as well as developments that occur over longer time periods.
For example, the invention makes it possible to determine a long-term change in a mechanical play caused, e.g., by an increasing state of wear. The determination of the amount of play, in turn, allows play-dependent factors such as a reference signal and/or offset signal and/or constant value to be adapted to the long-term change.
As a further preferred concept under the invention, the processing- and/or evaluating device processes the data from different detection time segments and/or from different operating phases selectively according to certain criteria.
As a particularly preferred concept, the data determined by the detector system are collected and processed over the entire operating life of the motor vehicle.
According to a further preferred embodiment of the invention, the intent-to-shift detection device has the capability to generate a shift lever signal representing the movement and/or position of the shift lever. The shift lever signal can, e.g., be proportionate in magnitude to the current displacement of the shift lever from a reference position. With particular preference, the displacement is determined only as a positive data value. However, the scope of preferred concepts also includes the case where the shift lever displacement is determined in a positive and negative direction. With particular preference, the shift lever displacement is determined in terms of a transformed measuring unit, for example as a number of increments. Particularly preferred is an arrangement with a shift lever increment counter which can be reset to zero at predetermined times and/or in predetermined situations.
Such a situation exists, for example, if the shift lever is detected to be in a position corresponding to one of the shift levels and/or to the neutral state of the transmission. Particularly preferred is a position where the shift lever is force-free, i.e., where no forces are acting on the shift lever.
In accordance with the invention, it is preferred if the intent-to-shift detection device further generates a reference signal. By comparing the reference signal to the shift lever signal, it is possible to detect when a gear-shifting process is about to occur in the transmission. Based on this detection, a signal to a downstream actuator system can be generated already at an early time to activate other devices participating in the gear-shifting process.
With particular preference, the reference signal is generated as a summation of a filter signal and/or a constant value and/or an offset value. It is particularly preferred if the filter signal is generated as a dependent function of the shift lever signal. For example, the filter signal may be generated by processing the shift lever signal through a digital/analog-filter with a time lag. Particularly preferred is a filter in which the signal is linearized. According to the invention, a PT1 filter stage is used as an especially preferred means of generating the filter signal from the shift lever signal. According to another preferred embodiment of the invention, the time lag of the filter is adjustable. It is further particularly preferred if the reference signal is based directly on the shift lever signal, or if the reference signal is formed independently of the shift lever signal.
It is further preferred if the constant value and/or the offset signal of the reference signal are adjustable.
With particular preference, the constant value is matched to the elasticity of the shift rod mechanism and thus to the potential oscillation amplitude. A particularly preferred choice for the constant value is such that, with the typical oscillations of the shift lever during the operation of the vehicle, there will be no cross-over between time profiles of the shift lever movement signal and the reference signal that follows the shift lever signal with a time lag.
With preference, the offset signal is dependent on the torque of the drive source. If the drive source is a combustion engine, it is particularly preferred if the offset signal is set or adjusted dependent on the current throttle valve position.
According to another preferred embodiment of the invention, the constant value and/or the offset signal can be set or adjusted during an operating phase of the motor vehicle. It is particularly preferred if the constant value and/or the offset signal can be adapted to the values, data, or signals determined or calculated by the detector system.
The latter concept is advantageous because it allows the reference signal to be determined on the basis of highly up-to-date values for the play in the force-free extreme positions of the shift lever. This, in turn, is conducive to a more reliable and accurate detection of an impending shift process.
The intent-to-shift detection device preferably sends an intent-to-shift signal to an actuator system arranged downstream, if predetermined criteria are met which are indicative of an intent to shift gears.
With preference, an intent-to-shift signal is emitted when there is a cross-over between the time profiles of the shift lever signal and the reference signal. It is further particularly preferred if a cross-over is artificially generated in the presence of certain situations. For example, it is a preferred concept under the invention, to generate an artificial signal or to send a separate intent-to-shift signal to the downstream actuator system in cases where the shift lever is moved so slowly that a cross-over can never occur or will occur too late because of the time lag of the reference signal. As a part of this concept, it is particularly preferred if the speed of the shift lever movement is monitoredxe2x80x94preferably on a continuous basis. Preferably, an intent-to-shift signal of the kind just described is generated if the speed of the shift lever, preferably for a movement in a shifting segment, is greater than zero and less than a predetermined limit.
In a further preferred embodiment of a motor vehicle according to the invention, the intent-to-shift detecting device will not yet emit an intent-to-shift signal at the time of a cross-over between the shift lever signal and the reference signal, but will emit the signal only after a predetermined waiting time, if the intent to shift gears has not been revoked by a an appropriate cancellation signal. The waiting time, which is preferably adjustable or controllable begins at the time of the cross-over.
With preference, a cancellation signal is generated if a reversal of the direction of shift lever movement has been detected. As a particularly preferred part of this concept, the respective lengths of time or distances of travel in the back and forth directions of shift lever movement are taken into account for the decision whether or not a cancellation signal is to be generated. For example, the main direction of movement of the shift lever may be given special weight in the decision for or against generating a cancellation signal.
This makes it possible, e.g., to deal with situations where there is a momentary reversal in the movement of the shift lever, but where otherwise the speed and displacement as well as the general direction of the shift lever movement clearly indicate that a shift process is to be initiated. In this case, the intent to shift will continue to be recognized and a shift-intent counter will not be reset to zero unless further conditions are present.
A situation of this kind can occur during the operation of a vehicle, e.g., if the driver changes his grip on the shift lever to a more comfortable position during the shift process and thereby momentarily moves the shift lever in the opposite direction, but immediately resumes pushing the lever forward towards the intended shift level.
It is also preferred if a control signal is emitted whenever a reversal in the shift lever movement has been detected. The control signal could be used, e.g., to reset a shift counter that was activated at the cross-over between the reference signal and the shift lever signal.
It is likewise among the preferred concepts of the invention to monitor factors like the driving torque and/or the torque load and/or the throttle valve position and to generate a control signal or cancellation signal if these factors are found to run in a direction that contradicts the intent to shift.
With particular preference, the positions of the shift lever are detected and registered in a storage memory for at least one force-free neutral position of the shift actuator shaft. With this arrangement, it is particularly preferred if the shift actuator shaft is held in the force-free neutral position by a detent device to give a substantially reproducible definition to the force-free neutral position. This makes it possible to use fluctuations in the shift lever position for the determination of the shift lever play.
According to a particularly preferred embodiment of the invention, the detector system has a group-assignment characteristic to assign the collected or calculated or detected data values, such as shift lever positions and/or shift lever movements, to at least one group.
It should be noted that in the context of the present. invention, the terms xe2x80x9cgroup-assignment characteristicxe2x80x9d and xe2x80x9cgroupxe2x80x9d encompass a broad range of meanings.
Thus, a group-assignment characteristic can, for example, assign collected or calculated values to a certain group based on specific existing criteria, e.g., based on conditions under which the data were collected and/or calculated, where the group is specifically distinguished as the recipient of all data that meet the specific group""s criteria.
A group-assignment characteristic in the sense of the invention may also include, e.g., that an assignment of the data in the strict sense of the word is not taking place but that the incoming data are already classified at the time of collection, based on the nature of the data. The classification of a set of data may be, for example, that the data were collected when the transmission was at a predetermined level, e.g., in neutral, the shift lever or a component coupled to the shift lever was in a force-free position, and the shift lever was being moved slowly or was in a stationary condition.
The invention also includes the concept that the shift lever position data are not separately classified or checked according to criteria, but are simply registered as values that were collected in the presence of the preset conditions.
It should be noted in this context that the force-free condition of the shift lever as described above may be ascertained, e.g., from the fact that a signal of the transmission-mounted sensor for the shift movement deviates from a neutral value (defined, e.g., as 512 increments) or from an other unequivocally defined and preferably reproducible position by no more than a predetermined number of measuring increments.
The term xe2x80x9cgroupxe2x80x9d may, e.g., relate to a storage register section in which, e.g., detected data values meeting specific criteria are stored. However, the group concept may also include the understanding that values such as shift lever positions are collected only if specific conditions are present, in which case the collected values are automatically assigned to a group that corresponds to the specific conditions. The specific conditions under which data are collected are, e.g., the aforementioned conditions identified as xe2x80x9cshift level=0 (neutral)xe2x80x9d; xe2x80x9cshift lever in a force-free conditionxe2x80x9d; and xe2x80x9cslow movement or no movement of the shift leverxe2x80x9d,
In a preferred embodiment of the invention, shift lever position data are collected under the conditions identified as xe2x80x9cshift lever in a force-free conditionxe2x80x9d; and xe2x80x9cslow movement or no movement of the shift leverxe2x80x9d and assigned to different groups in correlation with different shift levels including the neutral as well as other shift levels.
For example, the invention proposes a group in which the maximum values of the shift lever position are registered and another group in which the minimum values are registered. A specific shift lever position is designated as representing the border value between the group of maximum values and the group of minimum values. Under a preferred concept, all values greater than the border value are lumped together into the group xe2x80x9cmaximum values of the shift lever positionxe2x80x9d, and all values below the border value are lumped together into the group xe2x80x9cminimum values of the shift lever positionxe2x80x9d.
It is likewise preferred to have a group xe2x80x9cmaximum values of the shift lever positionxe2x80x9d in which all positions are registered that lie within a specified range. For example, the lower limit of the range is the previously found maximum shift lever position, while the upper limit of the range exceeds the value for the lower limit by a predetermined amount of, e.g., one increment. When a value is found to lie within this prescribed range, the lower limit of the group xe2x80x9cmaximum values for the shift lever positionxe2x80x9d is replaced by the new value, while the upper limit is raised accordingly (e.g., to the new value of the lower limit plus one increment).
As an alternative or as an additional possibility, it is also preferred to have a group xe2x80x9cminimum values for the shift lever positionxe2x80x9d, in which values for the shift lever position are registered if they fall within a prescribed range. According to the preferred concept, the upper range limit of the group xe2x80x9cminimum values for the shift lever positionxe2x80x9d corresponds to the previously established minimum value for the shift lever position, while the lower limit is set at a prescribed distance from the upper limit, e.g., at the upper limit minus one increment. Under the preferred concept, if a detected value of the shift lever position falls into this range, it will be used to replace the upper limit of the range, while the lower limit is changed accordingly, e.g., to the new upper limit minus one increment.
Also preferred is a concept where instead of the inner limits, the outer limits of each range are replaced by new values so that the plus/minus signs for the respective numbers of increments are reversed.
It is particularly preferred according to the invention, if the play of the shift lever is determined based on a dynamic change of the ranges of the aforementioned groups. With preference, values that are not assigned to either of the groups xe2x80x9cmaximum values for the shift lever positionxe2x80x9d or xe2x80x9cminimum values for the shift lever positionxe2x80x9d after they have been detected and tested according to the group criteria are discarded, i.e., not entered into the storage register.
According to a preferred embodiment of the invention, the time profile of the range limits is retained as stored information. Likewise among the preferred concepts, the time profile of only one of the range limits is entered into a storage register. For example, only the maximum and minimum values of the shift lever positions, i.e., one range limit at each end, are stored as a function of time.
In a particularly preferred embodiment of a motor vehicle equipped with a detector system according to the invention, the play or deviation of the shift lever position is detected for the movement of the shift lever between two shift levels.
This means in particular, that the minimum as well as the maximum displacement travel of the shift lever is detected for a direct shift from a predetermined first shift level to a predetermined second shift level.
As a preferred way of practicing the foregoing concept, the minimum and maximum positions are determined for the two shift levels.
Preferably, the foregoing determination is performed under the previously stated conditions where one of the shift levels is the neutral level and where the shift lever is force-free and moving either very slowly or not at all.
By taking the difference between the maximum and minimum positions for each of the two shift levels and then adding the two differences, the maximum variation in shift lever travel is obtained that can occur in different shift processes from the prescribed first gear level to the prescribed second gear level and vice versa.
The maximum variation in shift lever travel can be used to calculate the play in the same way as the maximum/minimum difference within a gear level is calculated. Furthermore, the maximum variation in shift lever travel is preferably used in the determination of the reference signal.
In accordance with the invention, it is particularly preferred if the maximum difference or maximum variation is calculated for every possible shift process, i.e., in particular for every possible combination of one gear level with another.
In accordance with a particularly preferred embodiment of the invention, the group-assignment characteristic has a part that works as a selection- or elimination characteristic. The selection/elimination characteristic has the purpose of selecting certain ones among the detected and calculated values for further processing. With preference, the selection/elimination characteristic employs prescribed selection criteria for deciding which values are to be processed further.
If the selection involves more than one selection criterion, the method of selection is preferably designed so that a value is selected for further processing only if all of the selection criteria are met.
Nevertheless, also included among the preferred concepts is the case where the selection characteristic selects a value for further processing if only one of a plurality of selection criteria is met.
It should also be noted here, that the term xe2x80x9cselection/elimination characteristicxe2x80x9d in the present context covers the same wide range of meanings as the term xe2x80x9cgroup-assignment characteristicxe2x80x9d.
It is especially preferred to have a certain selection criterion requiring that a measurement value or calculated value must lie within a prescribed range in order to be selected.
For example, in a particular case this criterion may require that a measured value lies in a range between a lower limit corresponding to a previously registered maximum value and an upper limit that exceeds the previously registered maximum value by a given incremental difference. To complete the example, an analogous selection criterion may also be used for the minimum value and the associated selection range. Also among the preferred concepts, the selection criterion may require a measured or calculated value to lie in a range delimited between an upper limit that exceeds the previously registered maximum value by a given incremental difference and a lower limit that undercuts the previously registered maximum by a given incremental difference.
Likewise preferred is a selection criterion which allows a detected or calculated value to deviate from an average value of previously registered and/or selected values by no more than a first amount in the positive direction and by no more than a second amount in the negative direction. The range of preferred solutions includes the case where the first and second amounts are equal.
Preferably, the average value is calculated as the arithmetic mean, i.e., the quotient between the sum and the count of the previously registered individual values.
Also among the preferred concepts, a weighted average may be used instead of the arithmetic mean, using a prescribed weight function. For example, the individual values may be weighted differently dependent on their distance from a predefined reference point.
In accordance with a preferred embodiment of the invention, the detected and/or selected values are accumulated into a history, where the term xe2x80x9chistoryxe2x80x9d is meant to encompass a broad range of meanings.
Thus, the term xe2x80x9chistorical storagexe2x80x9d in the present context means, e.g., that the detected or calculated values are registered in chronological sequence.
The term xe2x80x9chistorical storagexe2x80x9d further encompasses the possibility where values detected or determined in the past are stored without regard to their chronological sequence.
According to a particularly preferred embodiment of the invention, the values that have been determined, calculated or processed are erased at predetermined points in time. As an example, in a certain embodiment the values may be stored only over the length of an individual operating phase. Also preferred is the concept of storing data only if they have a certain relevance with respect to further evaluation measures. This may mean for example, that only the current maximum and minimum values are registered while values in between may be ignored.
According to a particularly preferred embodiment of the invention, xe2x80x9cerasedxe2x80x9d values are transferred to a long-term storage register, so that they remain available for special situations, e.g., to evaluate a long-term history.
A motor vehicle according to a particularly preferred embodiment of the invention is equipped with a noise-elimination device. The noise-elimination device allows the removal of noise components from the detected and/or calculated values, or from series of detected and/or accumulated values.
With particular preference, the noise components of signals are eliminated by taking an average of a plurality of individual values. The averages used for the elimination of noise components may be weighted averages, but the scope of preferred solutions also includes non-weighted averages.
Preferably, the individual values entering into an average are selected according to a given characteristic. For example, the characteristic may prescribe to take averages based on a certain number of consecutively detected individual values so that, e.g., the first ten detected or registered values would make up a first average, the eleventh through the twentieth value would make up the second average, and so forth.
It is also one of the preferred concepts to use each value in more than one average, for example by taking a first average based on values 1 through 10, a second average based on values 2 through 11, a third average based on values 3 through 12, and so forth. It should be noted that the foregoing selection characteristics for forming averages are meant as examples and that the invention encompasses a multitude of other possibilities of calculating an average.
According to a particularly preferred embodiment of the invention, only those individual values are processed into averages that were detected or collected under specific conditions, e.g., values that were detected while the transmission was at the neutral gear level (gear level=0) or, alternatively, at a specific gear level other than neutral, and while the shift lever was essentially force-free and the speed of shift lever movement was either zero or very small.
With preference, the averages discussed above are assigned to subgroups, whose criteria are essentially analogous to the criteria of the aforementioned groups.
It should be noted that the foregoing example, where ten individual values are combined into an average, is not to be taken as a limitation of the invention.
In principle, an essentially arbitrary number of individual values can be used to calculate an average value.
With particular preference, an average value is made up of individual values that meet a prescribed criterion. For example, an average is taken of individual values representing the shift lever position at a specific gear level (which can be the neutral or any other gear level). It should be noted that a specific gear level or specific condition should preferably be understood to include a small range of variation that can be caused, for example, by a mechanical play.
It is particularly preferred to use the averages for the determination of the minimum and maximum shift lever positionsxe2x80x94preferably within a given gear levelxe2x80x94in an analogous manner as described above for individual values.
It should be noted that, in essence, every operation that was described above for individual values can also be performed with the corresponding average values, and vice versa.
According to a particularly preferred embodiment of the invention, a certain number of individual values is considered to determine an average in a manner where the actual calculation of the average is based on only a part of the values considered.
As a particularly preferred example of the foregoing concept, the largest and the smallest of the individual values considered are disregarded in the calculation of the average. This means that, e.g., of ten values considered, only eight are entered into the calculation of the average. However, the range of advantageous possibilities according to the invention also includes the option of disregarding the two smallest and/or largest, or disregarding the three smallest and/or largest of the individual values.
The purpose of the foregoing way of calculating an average is to keep statistical outliers from entering into the calculation.
As a further preferred concept, certain intervals between individual values are taken into account in determining which values are to be considered in calculating an average.
According to the invention, to apply the foregoing concept in a case where one had, e.g., n=10 individual values, one would establish the difference between the largest and the smallest of the ten values. The largest of the ten individual values will be entered into the calculation of the average only if the interval I between the largest and the second-largest individual value is less than one-ninth of the aforementioned difference between the largest and smallest of the ten values, or generally if I less than [largest value-smallest value]/(nxe2x88x921). The smallest individual value, likewise, is entered into the calculation of the average only if the interval between the smallest and the second-smallest individual value meets the aforementioned condition. According to a particularly preferred embodiment of the invention, the minimum values and the maximum values of the averages for specific conditions are entered into a max/min storage device or storage register.
A specific condition in the sense of the foregoing paragraph may encompass, e.g., that the individual values were detected while the shift lever was in an essentially force-free state, the transmission was at gear level zero (neutral), and the speed of shift-lever movement was zero or very small.
Another specific condition in the sense of the foregoing paragraph may require that the individual data values were detected while the shift lever was in an essentially force-free state, the transmission was at a gear level other than zero, and the speed of shift-lever movement was zero or very small. Further preferred is an arrangement where max/min storage registers are correlated with specific gear levels.
With preference, the maximum values and minimum values in the max/min registers are updated if a larger maximum value or a smaller minimum value has been found.
The relevant considerations for updating or replacing previously stored maxima and minima with new values as described above for maxima and minima of individual values are likewise applicable to the maxima and minima of the averages. In particular, a maximum or minimum value of the averages is replaced only if the new maximum- or minimum value deviates from the previously stored value by no more than a prescribed amount, e.g., by one measuring increment.
It should be noted that a measuring increment is, for example, four tenths of a millimeter.
According to a particularly preferred embodiment of the invention, the play-detecting device determines at least one amount of play based on the maximum- and/or minimum values of the registered or detected individual values or based on the average values. With particular preference, the play that is being determined is the play of the shift lever.
According to a particularly preferred embodiment of the invention, the play of the shift lever can be determined separately for each gear level.
With particular preference, the play in the neutral position is taken as representative for the absolute amount of play of the shift lever and, accordingly, the play is preferably determined only for the neutral position.
It is preferred to store the values for the amounts of play in each gear level and also, to update the stored values when a change has been found in an amount of play.
With particular preference, the play is determined for the force-free positions of the shift lever in more than one gear level, preferably for all gear levels other than the zero level.
According to a particularly preferred embodiment of the invention, the amounts of play for the individual gear levels are compared, and an absolute play of the shift lever is determined as the maximum among the amounts of play for the individual gear levels.
It is also particularly preferred to store only the absolute amount of play of the shift lever and, if a larger amount is subsequently determined, to update the stored value of the absolute amount accordingly.
It is also preferred to store the time profile of the absolute amount of play to make it available for a long-term evaluation.
According to a particularly preferred embodiment of the invention, the reference signal is established dependent on the amount of play, e.g., dependent on the play of the shift lever at a given gear level, or dependent on the absolute play of the shift lever.
According to a particularly preferred embodiment, the reference signal is, in essence, continually adapted to changes in the detected amounts of play, particularly while the vehicle is in operation.
According to a particularly preferred embodiment of the invention, the value for the play is entered into the calculation of the offset signal.
It is likewise preferred to use the value for the play in determining the constant value.
With particular preference, the play is determined as the difference between correlated minimum- and maximum values.
With preference, the play of the shift lever in a force-free position within a gear level is determined as one-half of the difference between the maximum value and the minimum value of the possible shift lever positions for that gear level.
It should be noted that while shift lever positions are preferably detected in a force-free state, the scope of the invention also includes arrangements to detect strain, typically of a small magnitude.
As a general note, wherever the word xe2x80x9corxe2x80x9d is used in the present context in reference to features of the invention, it may be used either in the Boolean sense (one or the other or both) or as an exclusive xe2x80x9corxe2x80x9d (one or the other but not both).
It should further be noted that the terms xe2x80x9ccontrolxe2x80x9d and xe2x80x9ccontrollingxe2x80x9d as well as derivatives of these terms are used with a wide range of meanings, including in particular the concepts of regulating and/or controlling as used in German Industry Standards (DIN).
The novel features that are considered as characteristic of the invention are set forth in particular in the appended claims. The improved apparatus itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain presently preferred specific embodiments with reference to the accompanying drawing.